Process for preparing substituted carbazole derivatives



atet V ;z,aiiss Patented July 5, 1960.

A PROCESS FOR PREPARING SUBSTITUTED CARBAZOLE DERIVATIVES Rolf Kallischnigg, Hamburg, Germany, .assignor to Chemische Fabrik Promonta G.m.b.H., Hamburg, Germany, a firm of Germany No Drawing. Filed June 25, 1957, Ser. No. 667,957 Claims priority, application Germany June 27, 1956 Q 9 Claims. (Cl. 260-2932) Naomi V wherein the carbazole is attached either directly in the 3- or 4-position of the piperidine radical (x being 0), or in the 2-, 3- or 4-position of the piperidine radical over a hydrocarbon chain consisting of one or two methylene groups (x being 1 or 2); .R, is a lower alkyl radical, preferably methyl radical; R stands for hydrogen or a lower alkyl radical; and R stands for H, lower alkyl, oxy or alkoxy groups or halogen;

It has been found that compounds corresponding to the above general formula can be prepared with advantage by the following steps:

(1) Carbazole, or a C-substitutcd carbazole, .islalkylated with a pyridyl halide or pyridyl alkyl halide, preferj ably chloride or bromide, in form of the bases or salts,

in the presence of alkaline condensing agents, such as alkali-metals, or their hydrides, amides, oxides or carbonates, in an inert solvent, e.g. aromatic hydrocarbons, orhigher ethers; v I

(2) The resulting pyridyl carbazoles or pyridylalkyl carbazoles are quaternarized at the pyridine nitrogen wherein R R and R have the meaning defined above, and X denotes the anion, e.g. chlorine or bromine.

It has been found that the novel process can be carried out with very good yields even in those cases, in which condensation with the piper-idine derivatives is connected with considerable difiiculties in view of their steric hindrance.

The following specification describes by way of example some specific embodiments of and best modes for carrying out the invention, to which the invention is'not limited.

EXAMPLE 1 I-alkyl piperidyl-fimethyl-carbazole I ALKYLA I'ION Pwz'dyl-3-methyl carbazola-Jn a 2-liter three-necked flask. provided with stirrer, reflux condenser and dropping funnel 102 grams of carbazole, 35 grams of sodium amide and 660 cm. ofdry Xylene are introduced. The mixture is heated to boiling under stirring and under reflux, until the greatest part of the carbazole is converted into the sodium compound;

. Subsequently 78 grams of pyridyl-3-methyl chloride in 500 cm. of xylene-freshly set free from 102 grams of pyridyl-B-methyl chloride hydrochloride are-; dropwise addedduring one hour. Boiling is continued for an additionalhounthe reaction product is decomposed with some alcohol and subsequently water, the xylene solution is abundantly washed with water and the base is extracted therefrom by means of dilute hydrochloric acid. The aqueous acid soluti'on--from which a considerable portion of the hydrochloride separates in crystalline form-is rendered alkaline with ammonia .and the separated base is taken up in chloroform. 'After drying with potassium carbonate and purification with active carbon, the chloroform is distilled 0d and the crystalline residue is recrystallized from acetic ester. 135 grams of pyridyl-B-methyl carbazole having a melting point of 117 C. are thus obtained.

QUATERNARIZATION "grams of pyridy1-3-methyl carbazole-are heated with 22 grams of methyl bromide in 500 cm. of acetone-for 4 hours in a glass autoclave to 50-70 C. The resulting quaternary saltseparates quantitatively in crystalline form and is recrystallized from alcohol-acetic ester. Melting point: 193 C. f

'(b) Pyridyl 3 --methyl carbazole-ethobromide. 50 grams of pyridyl-B-methyl car bazole' are heated in an autoclave with 25 grams of ethyl bromide'in 500cm. of acetone for 8 hours. The ethobromide separates in crystalline form and is recrystalliaed from alcohol-acetic ester. The yield amounts to of the theory and the melting point is 232 (3.. 7 V

(c) Pyridyl-3-methyl-carbuzole-n-propobromide. 10 gramsof pyridyl-Zi-methyl carbazole are heated with 5 grams 'ofn-propylbromide in 50 cni. of propylene carbonate for 12 hours to -120" .C. in a bomb tube. The quaternary salt which precipitates in a yield of';72%, is recrystallized from alcohol-acetic ester and melts at 193-194 C. V

V 7 HYDROGENAIION {(a) 1-methylpiperidyl-3-methyl carbazole.-l00 grams of pyiidyl-3-methylcarbazole methobromide are dissolved in 900 cm. diluted methanol and subjected to hydrogenation in an autoclave with Raney cobalt catalyst at 7'0-75 C. After the calculated amount of hydrogen is taken up, the catalyst is separated by filtration, the methanol is distilled off and the residue is rendered alkaline with ammonia. The separated base is taken up in ether, dried with potassium carbonate and treated with active carbon. By the introduction of hydrochloric acid gas the l-methylpiperidy1-3-rnethyl carbazole-hydrochloride is obtained in quantitative yield. After recrystallization from alcoholacetic ester, this compound melts at 250-251" C.

('b) l ethylpiperidyl-3-meihyl-carbzzzole.--l00 grams of pyridyl-3-methylcarbazole-ethobromide are dissolved. in 900 cm. of diluted methanol and subjected to hydrogenation in an autoclave'with'Raney nickel catalyst at melts at 124? ,c. and the yield amounts to 72% of the theory; T .r a

70-30 0. 'After the'taking u "of hydrogen is completed, the reaction mixture is filtered in hot condition;

The N-etl1ylpiperidyl-3rmethyl-cai'bazole hydrobromide crystallizes upon cooling andis recrystallized from metha- 1101. -,The yield amounts ,to' 98 ot the theory; Melting point: 238 C;

The corresponding hydrochloride prepared from the' of the hydrochloride by introduction ofhydrogen chloride. By recrystallization from alcohol-ether, 85' grams of N-methylpip eridyl-4-methylcarbazole' hydrochlorid having amelting point of 79 C. are obtained.

(b) Lethylpiperidyl-4-methyl-eafbazole, 50 grams of pyridyl-4-methylcarbazoleiethobromide are dissolved in 500 cm. of diluted'methanol andfsubjeotedr to hydrohydrobromide overthe'oily base melts-after recrystal lization from alcohol-acetic ester"'at 218"? C.

(c) 1m-propylpiperidybi methyl-caybazole.+50. grams of fpyridyl-3 methylcarbazole-n-propobromide are dis solved in 400 cmfi of diluted methanol andsubjected to hydrogenation With Raney cobalt in an autoclave at 70-80? C. After the takingup of hydrogenis icompIeted the reacti n mixture is filtered in hot condition,

subsequently washed with methanol, the methanol is dis tilled ofi and'theresidue is rendered alkaline with alkali. j The base thus separated istaken up in. ether, dried with I potassium; carbonate and purified with active carbon.

from the ether solution thebase is precipitated 'in. the "form, of hydrobromide by the introduction of hydrogen i ester, melts at 227- 228 Q-"The ieIa-amQuniS'tOQs rz fiask' providedwithstirrer; reflux condenser, and a feeding device, 102. grams of carbazole, 85 grams of sodium foxide, and;9 00 'c'mFof xylene are 'introduced. Tothe mixture,'which,isheated to boiling, 100 grams of finely pulverized .pyridyl-4 methyl 1 chloride hydrochloride are gradually added in very small portions during 1- 2 hours.

, Afterthe'addition completed, boiling is continued for 1i hour,,-Ia'nd,the mixture is. thencooled and decomposed genation in the presence of palladium' (in-carbon 'in an.

autoclave at' 25 4i) C. The hydrogenating solution is 'freedfrom methanolfijs rendered alkaline with aminonia and the separatedoilis taken up in ether. After'dryin'g the ether solution with potassium carbonate, the b'aseis separated in form of the hydrochloride by; means 1 of L I hydrogen chloride. The ba se is recrystallized f rom 'v Pyridyll-mthyl-carbazola ln a 1 2-liter three-necked 20 I 'Pyridyl-2-methyl-carbazole.-Into' a 2-liter three-necked alcohol-acetic ester. The yield amounts to 89% of -the flask provided with stirrer, r eflux condenser and dropping funnel 102 grams of carbazole, grams of sodium amide and 500 cm toluene are introduced. The mixture is heated to boiling under stirring and under reflux fortwo hours, whereupon 78 grams of pyridyl 2-methy1carb'azolein7500 cm. of toluene are 'dropwi se gradually introduced during one hour. This last mentioned compound has to be freshly prepared by decomposition andsaturation of a concentrated aqueous solution of 103 grams of pyridyl-2-" methyl-chloride hydrochloride, with potassium carbonate, 'V'After the addition is completed, boiling of the reaction mixture, is continued for 30 minutes, whereupon said withfwater. T The xylene-solution is washed withv water and :extracted by shakingwith dilute hydrochloric acid.

'Iheacidaqueous solution istreatedwith active carbon 'and is rendered alkaline with .a solution of alkali or carbonates, orammoniar The separated ,oil is taken; up in ether, dried with potassium carbonate and treated again .ether, the desired compound is obtained as a crystalline residue,;which is recrystallized from 'isopropanol 'It I ouacbnamitizaim I i (a) Pyr idyl-4-methylcarbazble-methobromide.

grams :of; pyridyl-4-methyl carbazole and L gran1s of methylbromide are heated'iin' 500 cm; of acetonefor 8 hour's in' a glass autoclave to, vBil-Ml? C.-j: '-Il1e ,crystal 3.; lized quaternary saltis separated by filtrationand recrystallized from alc ohol The'yield amounts to 92% of the theory. Melting point; 236-237 f C.= a i 3 (b) Pyridyl 4 methyl-carbazole ethobrgmide. .i50

grams of pyridyl-4-methyl carbazole and 25 grams of 3 ethyl bromide are heated in 300 cm. of propylene car- 7 bonate in a glassautoclave to 100 C; for 16 hours; t The resulting quaternary compound separates as an oily sub- 7 stance and can be brought to crystallizationj by' trituration with 2-pentanone; llleyield amounts to 85%. of V the-theory and" the melting ipointpfthe substance'is a t1 inethylpiperidyl-4-mthylcarbqzble. 80 grams a pyridyl-4-methylcarbazole-methobromide are dissolved in tee i eise aaete, th 'ba s srrs ri s q aiwm 7 500cm. ct /diluted methanol and subjected to hydrofgenation in the presence. of Raney nickel. After the taking up .of hydrogen is completed, the hydrogenation isolation is filtered and concentrated by evaporation, renzldered'alkalinewith'a solution of alkali, and the separated p11 is taken up in ether. After drying the ether solutionv mixture is cooled and decomposed with little'alcohol and subsequently with water; The toluene. solution is washed with water andextracted by shaking with hydrochloric i acid. The hydrochloric ,acid solution is purified with active carbon and is rendered alkaline with ammonia. The

*QuA'rERNARrzATro clave to 7 0- 9 0 C. for 8 hours. The quaternary salt WhlCh' is quantitativelyiseparated in crystalline condition,

is filtered-OE and is recrystallized,from'alcoholeacetic te T e m n Point 226.. :21 i

" 1 methylpiperidyl-Zmethyl carbaz0lef-20D of pyridyl-Z inetl yl-carbazole-methobromide are dissolved in 'one liter of diluted methanol and' subjected to hydrO genatiou inthe'presence of Raney nickel or Ra'ney'cobalt atv 70-80 C. After taking 'up'of the calculated amount of hydrogen is completed, the solution is filtered and concentrated by evaporation. TheT's'yrup-like residue is diluted with water and is rendered alkaline with alkali or ammonia. .The separated base is'takenup in chloroform, dried 'with'pot'as'sium' carbonate and purified with active carbon. 'I'hecrystalline residueobtained by dis-' 'tilling off the-chloroform is recrystallized from isopropanol. 1-methylpiperidyl-2methyl-carbazole is thus obtain'ed in almost quantitative .yield with a melting point' of 107 0; a .7 i ,7 a

The base yields lwith inorganic or organic acids;- salts,

for example, thehydrochloride '(from' diluted isoprop a- 'nol) with ajmelting' point of 237-239'C.; the amidosulfonate (from diluted isopropanol) with 'a meltinglpoint or 117-119 C.; and the lactate (from acetic ester) a sl P et 921.131; lix; r

136 grams of pyridyl f 2-methylcarbazole (87% of the theory) are thus obtained with active-carbon, ifinecessary. After distilling on the in P e Pqim f 5 V. i Pyridyl-Z methybqarbczole-methobromidagrams L a or pyridyl-g-methylcarbazole and 42 grams )of methyl-. 1 'brOmideVareheatedinSOO cmfi 'of aceton'ein an'auto 5 EXAMPLE 4 1-alkyl-6-methylpiperidyZ-Z-methybcarbazole ALKYLA TION 6-methylpyridyl-2-methyl-carbaz0le.lnt0 a 2-liter three-necked flask provided with stirrer, reflux condenser and dropping funnel, 94 grams of carbazole, 7 grams of lithium hydride and 500 cm? of benzene are introduced. The mixture is heated to boiling under stirring and under reflux for 2-3 hours, whereupon 79 grams of 6-methylpyridyl-Z-methylchloride in 400 cm? of benzene are gradually dropwise introduced during one hour. Boiling is then continued for about one hour, whereupon the mixture is cooled and cautiously decomposed with water. The benzene solution of the base is thoroughly washed with Water and extracted by shaking with dilute hydrochloric acid. The dithcultly soluble hydrochloride of 6- methylpyridyl-Z-methyl-carbazole separates in crystalline form, is filtered oil? and recrystallized from dilute hydrochloric acid. The melting point is 219-220 C. The crude or pure salt is decomposed with ammonia, the base is taken up in ether, dried with potassium carbonate and purified with active carbon. The residue obtained by distilling ofi the ether is recrystallized from acetic ester. The yield of the base amounts to 75% of the theory and the melting point or" the base is 118 C.

QUATERNARIZATION 6-methylpyridyZ-Z-rrzethyl-carbaZole m ethbromide.- 100 grams of 6-methylpyridylr2-methyl-carbazole are subjected to quaternarization with 50 grams of methyl bromide in 606 cm. of acetone by heating is an autoclave to 90-95 C. for two days. The separated salt is recrystallized from alcohol-acetic ester. The yield amounts to 71% of the theory and the melting point is 238-239 C.

HYDRQGENATION LG-dimethylpiperidy1-2-methyl-carbaz0le.l2O grams of 6-methylpyridyl-2-methyl-carbazole methobromide are dissolved in 900 cm? of diluted methanol and subjected to hydrogenation in an autoclave in the presence of Raney cobalt at 50-65 C. The hydrogenating solution is concentrated by evaporation, the resulting hydrobromide of the base to be prepared is decomposed with ammonia and the separated oil is taken up in ether. After drying and purifying in conventional manner the solution of EXAMPLE 5 I 1-alkyl-5-methylpiperidyl-Z-mathyl-carbazole ALKYLATION 5 methylpyridyl-Z methyl carbaz0le.-lnto a 2-liter three-necked flask provided with stirrer, reflux condenser and dropping funnel, 94 grams of carbazole, 90 grams of. sodium oxide and 800 cm? of xylene are introduced. The mixture is heated to boiling, whereupon 100 grams of finely pulverized 5-methylpyridyl-Z-methylchloridehydrochloride are added gradually in very small portions during two hours. Boiling is then continued for one hour. The reaction mixture is now decomposed with water and is abundantly washed with water in order to remove quaternarized ingredients. Upon treatment of the basic Xylene solution with hydrochloric acid the hydrochloride of 5-methylpyridyl-Z-methyl-carbazole separates in crystalline form. It is filtered off, decomposed with soda, the separated base is taken up in ether and dried with potassium carbonate. The crystalline residue oi the ether solution is recrystallized from acetic ester. The yield amounts to 88% of the theory and the 5- methylp'yridyl-2-rnethyl carbazole melts at 81-82 ,C...

QUATERNARIZATIQN S-metlzylpyridyl-Z-methyl-carbazole methobramida-a 100 grams of 5-methylpyridyl-2-methyl-carbazole are quaternarized by heating in an autoclave with 50 grams of methyl bromide in 400 cm. of alcohol for 8 hours. After concentration by evaporation of the alcoholic solution the methobromide separates in crystalline formupon cooling. It is recrystallized from alcohol. The yield amounts to of the theory and the melting point is 258-260 'C.

HYDBQGENATION 1,5-dimethylpiperidyl-2-methyl-carbazole.l30 grams of 5.-1nethylpyridyl-Z-methyl-carbazole-methobromide are dissolved, in one liter of methanol and subjected to hydrogenation in the presence of a platinum catalyst in an autoclave. at room temperature, e.g. 15-25 C., until the calculated amount of hydrogen is taken up by hydrogenation. The solution is filtered in hot condition, the filtered solution is concentrated by evaporation and yields upon cooling in quantitative yield the l,5-dimethylpiperidyl-2- methyl-carbazole-hydrobromide. Upon recrystallization from water this compound melts at 263-264 C. The base can be obtained from the salt in conventional manner and melts after recrystallization from benzine at 106-107 C.

EXAMPLE 6 (1 '-alkylpiperidyl-2-methyl) -3-mezhylcarbazole,

tALKYLATION (Pyridyl-2'-methyl-)-3-methylcarbazole.lnto a 2-liter flask provided with stirrer, reflux condenser and dropping funnel 45 grams of 3-methylcarbazole, 13 grams of sodium amide and 400 cmfi of xylene are-introduced. The mixture is heated to boiling under stirring and under reflux for two hours whereupon 38 grams of pyridyl-Z- methylchloride in 300 cm. of xylene are gradually drop- Wise added during 30 minutes. The last mentioned compound should be freshly prepared by setting it free from 50 grams of pyridyl-2-methylchloride-hydrochloride. Subsequently, boiling is continued for an additional hour whereupon the reaction product is cooled and decomposed with little alcohol and subsequently with water. The xylenesolution is thoroughly washed with water in order to remove quaternarized products. It is then extracted by shaking with dilute hydrochloric acid and the acid aqueous solution is purified with active carbon. The base to be prepared can be separated in oily condition, by rendering the solution alkaline with ammonia, an alkali hydroxide or alkali, metal carbonate.- The base is taken up in ether, dried with potassium carbonate and purified with active carbon. .By distilling olf the ether a crystalline residue is obtained which is recrystallized from acetic ester. 53 grams of (pyridyl-2-methyl-)-3 methylcarbazole are thus obtained with a melting point of 103-104 C. Y I

QUATERNARIZATION (Pyridy 1-2 '-m efhy 1-) -3 -m efhylcarbazole-meth ohromiae. 40 grams of (pyridyl-2'-methyl)-3-methylcarbazole are. quaternarized by heating in a glass autoclave with 20 grams of methylbromide in 300 cm. of acetone to C. for 8 hours. The salt, which separates, in crystalline. form, is recrystallized from alcohol-acetic. ester. The. yield amounts to. 77% of the theory and the melting point. is 220-221? C.

HYDRQGENATION (1 methylpiperidyl 2 methyl 3 methylcarbazole.-30 grams of (pyridyl-2-methyl-) -3-methylcarbazole-methobromide are dissolved in 250 crnfi of diluted, methanol and subjected to hydrogenation in the presence of Raney nickel at 70-80 C. until the taking up of hydrogen is completed. The hydrogenating solution is filtered in hot condition and completely evaporated. The residue is taken up in water, rendered alkaline. with. an, alkaliand;

' isms-200 c. a

the separated base is taken up in ether or benzene. wThe crystallineiresidue obtained by distilling oil the solvent isrecrystallized from benzine or acetic ester. The yield amounts .to 91%"of thetheo'ry and the melting point is (Pyridyl-i-methyL)-3-meth0xycarbaz0le.lntol a 2- liter flask provided with stirrer, reflux condenser; and

dropping funnel 51 grams of S-niethoxy-carbazole, gramsof'sodium amide and 400 cm? of xylene, are introduced. ;A'fter "boiling for 2 hours 38 grams of pyridyl- 2-methylchlor'ide in 500 cm. 10f Xylene are gradually 'dropwiseadded; After continued boiling for one hour,

the; reaction mixture is cooled and decomposed with alcohol and subsequently with water. The xylene solution is abundantly washed with ,water and the'b'ase to be prepared is subsequently extracted therefrom by shaking with a dilute strong acid. After purification of the salt solution-with active carbon, the base is freed, taken up in ether, dried with potassium carbonate and the ether is distilled off. Thecrystalline residue is recrystallized from isopropanol. 61 gramsof pyridyl-2'-methyl-3-methoxycarbazole are thus obtained with a melting pointtof QUA TERN ARIZATION (Py'rz'dyl '2. methyl L l 3 rhethbxycz'zr bazole methatbromida-SO grams of (pyridyl-2-methyl-) -3methoxycarbazole, grams ofmethylbromide and 200 cmfi, of

' aceticester areheated inaglass autoclave to 100 C. for 8r-hours. The crystallized methobromide is recrystallized .from alcohol-acetic ester or isopropanol. V The yield amount's t'o 96% of the; theory and the melting point 7 HYDROGENATION 1' Fj inethylpipr idyl :2 methyl 3 mthoxy Earlzazole-dl) grams of (py1idyl-2'-methyl-)-3-methoxycarbazole methobromide are dissolved in 500cm. of

vmethanol of 50% and subjected to hydrogenation in an a 1 autoclave in the presence of Raney cobalt at 75 C. until thetaking up of hydrogen is completed. The solution is filtered in hot condition and subsequently concentrated.

by evaporation,"diluted with water and rendered alkaline with-an alkali. The separated oil is taken up in ether,

. dried with'ps'tasa carbonate and'plm'fid with {carbon The ether is"distilled:.ofi"'and the residue is treated 'with hot benzine; Thefresulting crystals are recrystallized from acetic ester-benzine. The yield amounts 4 88%of the and the melting point is 90-919 C.

l EXAMPLE 8 4 "j(l -ttlkylpiperidyl-i methyl)-2-clilorocarbazole LALKYLATTON Pyridyl-2-methyl-)-2-chlorocarbazofe.+lnto a 2-liter L flask provided with stirrer; reflux condenser and dropping Zfu'nnel 51 grams of Z-chlorocarbazoleL, 12 grams of sodiumamide and 50 0 cm. of benzene are introduced and the mixture is heated to boiling'und'er stirring and-under wellicooled solution'of' 38 grams of pyridyl-Z-methylchlo- W rid'ejin' 4t) 0j cm. of benzene are gradually added drop- Wise during onejhour and boiling is then oontinued for one I 7 additional hour; 7 The reaction solution is cooled, decomposed with alcohol andwater and repeatedly, washed with water. Upon treatment of the benzene .solution with dilute hydrochloric acid, (pyridyl-Z-m'ethyl)-2-chlorocar- V bazole-hydrocliloride .js'eparates crystalline form.- It

is recrystallized from anute' y acid-r with" the addition offactive carbong Theryield amounts to 81% of the theory and themelting point is 209 C. By de I composing thelh ydrochloride with ammonia, the base is *obtainedywhich -eafter recrystallization from acetic esteri "benzine melts atIO t-IOS C, p

QUATERNARIZA'T'ION (Pyridyl 2 Qmethyl --2 chloracarbazole ntethobromide.50 grams of'(pyridyl 2'-methyl-)-2-chlorocarbazo'le and 30 grams of methyl'bromide in 300 cm. acetone are quaternarized in an autoclave by heating to 80- 90 C. during 8 hours. The separated salt is filtered OE and recrystallized from alcohol-acetic ester. The yieldv amounts to 94% of the rtheory and, the melting point is C. a i

' DBQ E A NV balt'in an autoclave .at/5055 C. The hydrogenation solution is filteredin hot condition, the catalyst is washed with hot methanol and themethanol is distilled off; The residue is dissolved in water and rendered alkaline'with sodium :hydroxidesolution. The separated base is taken up in ether, dried with potassium carbonate and purified with active carbon. After distilling ed the solvent, the desired compounds is obtained as -a crystalline mass which is recrystallized from acetic ester-benzine or 'dibutylether." 2

. Into a 2-liter flask provided with stirrer, reflux condensen'feed device and thermometer, 63 grams of can a (1i mezhylpiperidyl 2' methyl 2 chlorocar l a'zole.50 grams of (pyridyl-2'+methyl-)-chlorocarbaa zole-methobromide are dissolved in 300 cm. of methanol I oft50% and subjected to hydrogenation with Raney 00+;

' bazole, 55 grams of sodium oxide and 700 cm. of p Q a V acid. 7

'- are introduced; The mixture is heated under stirringto 140 C., whereupon 100' grams of'finely pulverized 2-.

(pyridy1-2'-) -ethylbromide-hydrobromide are added grad-' ually in very small portions during one hour. Subsequently, heating 'is continued to 150 C. for two additional 7 hours. .After'coolingthe product is decomposed with' water, the Tetralin solutionis abundantly-washed withwater and extracted by shaking. with dilute hydrochloric From the hydrochloride, the-base can be obtained in con yentional .mannen. After recrystallization; from acetic ester-benzine, this base-melts at 77, C.

' QUATERNABIZATION V 7 (a) '2-(pyridyl-2'-)-erhylcarbazole-methobromidd-S .grams of 2-pyridyl-2'-ethyl-oarbazole and 22 grams of "bromide crystallizes from thealcoholic solution;

reflux for Bihours. Subsequently, a freshly prepared, 7

a of hydrogen is completed. The filtered solution-is i 7 from. methanol, the residueis diluted with water and rendered alkaline -by the addition, of an alkali. .The

methylbromide are heatedflin 300 cm. of alcohol in'a Upon 'concen- 1 glass autoclave to C. for 6 hours. trating the alcohol solution by evaporation,.the'metho- The yield'amounts to 96% of the theory and the melting point is 222-223" c. a 7

grams of 2-(pyridyl-2-) ethyl-carbaz'ole and- 25 grams of ethylbromide are quaternalized in 300 coilof acetone b'y heating to 100 for 12hours. A crystalline salt sep! 1 aratesand is recrystallized from alcohol} The yield' amounts to 82% of the theory and the melting point 182 -183? C. 7 V a 'i 7' nrnnoonnamrou (a) 2 (1": methylpiper idyl 2 j ethylcarba'zole.+

60 grams of 2-(pyridy1-2'-)-methyl carbazole-methobromide are dissolved in 500 cin. of diluted methanol subjected to hydrogenation in the presence of Raney.

nickel at 50-70 C. in an autoclave until the taking up The 2-(pyridyl-2-) -ethylcarbazole-hydrochloride crystallizes from the aqueous solution of hydrochloric acidf and is recrystallized from dilute ahydrochloriciacid. Needles having a melting point of 224-225 C. are'thus, obtained. The yield amountsto 65% 'ofthe theory;

h seha t ba s taken p in t r, dried nd pur fied. with active carbon. After distilling ofi the ether, the.- residue is re ys llized from acetic ester. 59 gr ms. of 2 (1'- methylpiperidyl-2-) -ethylcarb'azole having a melting point of 123-124 C. are thus obtained.

.(b). 2 a (1 ethylpiperidyl 2') ethylcarbazole. 45 grams. of 2-(pyridyl-2.'-) ethyl-carbazole-ethobromide are dissolved in 400 cm. of dilutedmethanol and subjected to hydrogenation in the presence. of palladium-carbon at room. temperature, e.g 18-25 C. The filtered. hydrogenation solution is; concentrated; by evaporation and then brought to crystallization. The resulting; 2 (l '-ethylpipetidyl- -ethylcarbazole hydrobromide recrystallized. from. lcohol nd. has th n me i s; P int, of 1.49- 151 c. The yield amounts to 6.6%. of; thetheory.

,0 2-(1 '-alkylpiperidyl-4'-) etbyltarba zqle ALKYLATION 2-(pyridyI-4) ethylcarbaz0le.Into a 2-li ter flask provided with stirrer, reflux condenser and dropping funnel, 6Q g ant Qt c rbazole, lQO. .grams or finely pulverized, dlii vpQ f tss ll jlu carbonate. and. 50.9. cm? of xylene are intro uced The mixtureis heated. under stirring to boiling and a freshly prepared solution of 50 grams of 2- (pyridyl-4) ethyl chloride are gradually dropwise added one. hour; Boiling is: then continued for 2. additional hours and the product is then. decomposed-with water. The xylene solution is thoroughly washed with water and is then extracted by shaking with dilute hydro chloric acid. The 2-(pyridyl-4'-) ethylcarbazole hydrochloride crystallizes from-the acid solution and is recrystallized from alcohol containing hydrogen chloride. The yield amounts to 62% of the theory and the melting point is 233-234 C. V

The base set free from the hydrochloride is recrystallized from acetic ester and melts then at 171-173 C.

QUATERNARIZATION 2 (pyridyl 4' ethylcarbazole meth0br0mide.30 grams of 2-'(pyridyl-4'-) ethylcarbazole and grams of methylbromide are heated in a glass autoclave in 300 cm. of acetone to 60 C. for 3 hours, The quantitatively separating crystalline methobromide is filtered off and recrystallized from alcohol-acetic ester. The melting point is 202-203 C.

I U HYDROGENATION '2-(1-methyipiperidyl-4'-) ethyl carbazolegrams of 2-(pyridyl-4-) ethylcarbazole-methobromide are dissolved in 300 cm. or methanol of 50% and subjected to hydrogenation with Raney cobalt at 50-60" C. in an autoclave. The hydrogenation solution is then separated from the catalyst and mixed with alcohol. The hydrobromide of the 2-(1-methylpiperidyl-4-) ethylcarbazole crystallizes in a yield of 92% of the theory and-after ,recrystallization from alcohol-has a melting point of 235-236 0. EXAMPLE l1 1-alkylpiperidyl-4-ctzrbazole ALKYLAJIION f Pyridyl-4-carbazole.-Into a 2-liter flask provided with stirrer, reflux condenser, dropping funnel and thermometer 56 grams ofca-rbazole, 18 grams of sodium amide and 800 crn. of tetralin are introduced. The mixture is heated under eificient stirring to 160-170 C. for 2 hours and at the same temperature 38 grams of freshly distilled 4-chloro-pyridine are then dropwise gradually added within 90 minutes. Boiling is'continued for 2 additional hours and the product is then decomposed with alcohol and water, the tetralin solution is abundantly washed with water and then extracted by shaking with hydrochloric acid. The acid solution is treated with active carbon and rendered alkaline with ammonia. The

46%. and amel iag neintof; 1.3.5 C-

QUA'JQEBNARI AT Q Pyridyl-4-carbazole-meth0br0mide.-30 grams of pyridyl-4-carbazole are heated with 16 grams of methyl bromide in 200 cm. of acetone in an autoclave to 60-70 C. The quaternary salt, which separates in crystalline form, is filtered oft and; recrystallized from alcohol. The yield amounts to 92% oi the theory-and the melting point is 246-247 C.

1-methylpiperidyl-4-carbazole.33 grams of, pyridyl- 4-eareazole-methobromide are dissolved in 400 cin. of diluted methanol and subjected to hydrogenation in the presence ofRaney' nickel at- 50-60 C. in an autoclave, until the calculated amount ofhydrogen is taken up. The filtered solution freed from methanol and rendered alkaline by the addition of sodium hydroxide solution. The separated oil is taken up in ether, dried with potassium carbonate, and purified with'aetive carbon. After distilling offthe ether; the residue is dissolved in hot benzine. The l-methyl-piperidyl-4-carbazole crystallized; Benz-inc melts at 151-152 C; The yield" amounts to 91% ofthe theory.

The novel products of the present invention are distinguished by valuable therapeutic efiects and can be used as such, or as intermediates in the preparation of substances for therapeutic treatments, as examples of which the following are mentioned: Use for raising the effect of analgesic substances, such as for example morphine, without aflecting the blood pressure and the vegetative system; increase of normal blood pressure and increase, of blood pressure lowered by the action of sympathicolytic substances, such as for example, chloropromazine. The dosage to be used corresponds in general to that conventionally used in the administration of the related phenthiazine derivatives and administration can take place for example per os by intramuscular injection. 1

Reference is made to my co-pending application Ser. No. 636,879, filed January 29, 1957 for Substituted Carbazole Derivatives.

The term diluted methanol is used in the present application to denote aqueous methanol containing water in the range of 5 to 36% by volume, and the term diluted isopropanol is used to denote aqueous isopropanol containing water in the range of 5 to 10% by volume.

The term tetralin is used to denoted tetrahydronaphthalene.

What is claimed is:

l. A process for the preparation of carbazole derivatives containing basic substituents and corresponding to the general formula V substituted car bazoles is alkylated witha 'c'o mpound 'se lected from the group consisting offpyridil halides pyridyl alkylhalides," in 'the presence of a an' alkaline con Apm ssas claimedmiaimf L n h py i' V halide and pyridylalkyl' halide used instep ;(a) is,se-' lected from the group consisting of the respective ch10 rides and bromides,

Oftherespectiye-hySesg- 5. A processes claimedfin OTHER REFEn BNcEs F 1 4 I Shapiro, et al'.: J.Phar m: Assoc. vol. 46

1957)',pages 333-6., J" 5 v v r I Major-Bode: Pyn'din. und seine 'Derivate :(1934); p:

I V V Lin, 1 *hazol and C sub's'titut'ed. carlzfa' zoles are used in the densing ageng'in'an inert-"solyent; ('b)- thepr'oduct's re 5 of the respective salts.;; sulting from step (a) ate quaternarized at-the pyridine 6: A process as el-ajmed in claimLl, in which the hyr" ,N- with' a lower alkyl halide; (C) the pyridinium salts drogenatiqn catalyst is selected from the group consisting resulting fi'om step' (b) and corresponding to the genof'nickel, cobalt,'pla tii1um and palladium. g i eral formula i L 7 p w 7. A process as claimedin claim 1,;in .whicl:i the mu 1 alkaline condensing agent is selected from. the group 1 I a consistingof alkali metals, their hydrides; amides, oxides y r, and carbonates i -8. Aprocess aswclaimedin'claim Lin which the solvent is selecte'dfrom the group consisting of aromatic hydrofi5 carbonsandhigher-ethersi 9. A processes claimedin claim 1,,in which X' stands v for a halogen'selected fi'om the 'group consisting of .i which R1, R R and'xhave the meaning defined above hlorme and bromme" v V v and X stands for. the anion, are subjected to hydrogenaw 'tionin the presence of 'a metallichydrogenation catalyst, 20 I Referenlces L in Q? Q??? p y in order to form acompound selected from the group 7 UNITED S AT PATENTS f qbnsist n Of y pip y carba oles n N-al y 2,687,414 "Cusic Au .'2'4; 1-9 53 p pe i y y a a 2 e -..-1 ,1; ,1 I i z 2,773,875 Finkelstein Dec.11'1,"1956 r 2'., P ss sc a m d nclaim-1,-iniwhich 1 t nds 2,784,185 Schuler' Mar; 5,1957

' mi h e hylvr-adicale r-fi I 25 r i 

1. A PROCESS FOR THE PREPARATION OF CARBAZOLE DERIVATIVES CONTAING BASIC AND CORRESPONDING TO THE GENERAL FORMULA 